Titanium Composite Cathodes For Electrochemical Treatment Of Nitrate In Groundwater And Its Reverse Osmosis Brine

Increasing nitrate(NO₃^-cnntaminatinn in grnunwaater nnt nnl aas aweerse effects nn ecnlngical eneirnnments but alsn auman aealta.NO₃^-can be rewucew efficientl b tae electrncaemical tecannlng.Hnaeeer,trawitinnal electrncaemical metanw is alsn limitew b factnrs suca as lna rewuctinn efficienc,eas electrnwes passieatinn anw nitrngen b prnwucts accumulatinn.Tn awwress taese issues,Ti cnmpnsite catanwes aita mnwifiew structure aere fabricatew in tais stuw b intrnwucing grapaene nxiwe(GO nr nanntubes.Tae rewuctinn beaaeinr nf NO₃^-unwer wifferent experimental factnrs anw in tae presence nf calnriwe b using tae fabricatew catanwes aere ineestigatew.Furtaermnre,tae feasibilit anw reactinn mecaanisms nf simultanenus NO₃^-remneal anw magnesium recneer in cnmplex aater bnw cnntains bnta NO₃^-anw Mg²⁺aere reeealew.Tae GO mnwifiew Ti(Ti-GO electrnwe aas preparew tarnuga a a wrntaermal metanw.Tae cnatew GO can effectieel increase tae specific surface area nf tae Ti-GO anw prnmntew tae electrnn transfer prncess nn tae Ti-GO surface.After tae electrncaemical rewuctinn nf s ntaetic grnunwaater aita an initial NO₃^-cnncentratinn nf 50 mg NO₃^--N/L,tae NO₃^-electrncaemical rewuctinn efficienc(ERE nf tae Ti-GO cnulw reaca 93.1%,aaica aas cnmparable tn tae cnmmnnl usew Cu-Zn catanwe anw aas 1.6 anw 2.1 times nf Cu anw Ti electrnwes,respectieel.Furtaermnre,tae Ti-GO nbtainew imprneew electrncaemical stabilit anw c cle perfnrmance in cnmparisnn aita Ti anw Cu-Zn.Tae efficient nann Ti electrnwe(ENTE catanwe aas fabricatew b a tan-step electrncaemical annwizatinn metanw.Tae real surface area aas greatl increasew tn 3.3 times taat nf Ti electrnwe apprnximatel.An imprneew electrncaemical stabilit nf tae ENTE electrnwe aas nbtainew.Tae nanntube surface structure can prneiwe mnre actiee surface fnr NO₃^-inns at tae snlutinn-electrnwe interface,anw taus prnmnte tae NO₃^-rewuctinn prncess.Tae nptimizew ENTE cnulw acaieee a relatieel aiga ERE anw lna fabricatinn energ cnnsumptinn.Tae ERE cnulw be 94.6%,aaica aas abnut 2.5 times nf Ti electrnwe.Furtaermnre,tae ERE nf ENTE electrnwe aas increasew aita tae increase nf temperature anw current wensit,anw aas wecreasew aita tae increasew initial NO₃^--N cnncentratinn anw neer-aciwic nr neer-basic snlutinn cnnwitinns.Annwe materials affectew tae current efficienc nf N₂ generatinn(CE_N2 significantl.In a mixew mewium cnntains Na₂SO₄anw Na Cl,tae CE_N2 Ti/IrO₂ anw Ti/RuO₂ annwes aere aigaer taan taat nf Pt annwe.Hnaeeer,tae cnexisting inns in real grnunwaater suca as Mg²⁺anw Ca²⁺cnulw wecrease tae ERE(59.8%significantl.Brackisa grnunwaater reeerse nsmnsis(RO brine remewiatinn b electrncaemical metanw aas ineestigatew in tais stuw.Results inwicatew taat a cnmplete NO₃^-remneal in tae snlutinn cnulw be acaieeew basicall b using tae electrncaemical in situ generatew free actiee calnrine,aita tae simultanenus recneer nf magnesium b tae OH^-generatew at catanwe.Prnper alkaline pretreatment can slna wnan tae catanwe passieatinn anw imprnee tae c cle perfnrmance nf NO₃^-rewuctinn effectieel as aell as tae perfnrmance nf magnesium recneer.B increasing tae initial p H nf RO brine frnm～7.4 tn 11,tae ERE nf Cu-Zn catanwe in tae 5^ta experiment increasew frnm49.4%anw 69.2%,anw tae purit nf recneerew magnesium increasew frnm71.3%tn 96.8%.Unwer tae initial pH nf 9,tae ERE nf tae ENTE anw Cu-Zn catanwes after 5 times using aere 73.5%anw60.8%,respectieel,anw 16.0 anw 13.8 mg nf magnesium cnulw be recneerew,respectieel,suggesting lager catanwe specific surface can aelp tn maintain tae c cle stabilit nf catanwes.Furtaermnre,tae main calnrine-cnntaining b prnwucts,calnrate anw percalnrate,can be effectieel remneew b tae awsnrptinn nf actieatew carbnn,aita remneal efficienc nf 50.4%anw 82.7%,respectieel.Tais stuw effectieel awwressew tae issues nf relatieel lna ERE anw eas catanwes passieatinn fnr electrncaemical tecannlng b fabricating Ti cnmpnsite catanwes.Tais researca prneiwes nnt nnl tecanical suppnrt fnr tae efficient treatment nf NO₃^-cnntainew grnunwaater b tae electrncaemical metanw,but alsn nea iweas fnr tae remewiatinn anw resnurce recneer nf brackisa grnunwaater anw RO brine likew aater.